TW202016263A - Liquid crystal composition and liquid crystal display using the same - Google Patents

Abstract

A liquid crystal composition and a liquid crystal display using the liquid crystal compound are provided. The liquid crystal compound includes first component and second component. The first component has at least one compound represented by formula (1), and the second component has at least one compound represented by formula (2):

,

, wherein R¹ , R² , R³ , R⁴ , X¹ , and X² , are as defined in the specification.

Description

Liquid crystal composition and liquid crystal display device using the liquid crystal composition

The present invention relates to a liquid crystal composition and a liquid crystal display device using the liquid crystal composition.

Liquid crystal display devices are widely used in various personal computers, personal digital assistants, mobile phones, televisions, car navigation devices, smart watches, etc. due to their advantages of thinness, light weight, low power consumption, low operating voltage, and no radiation.

In a liquid crystal display device, a liquid crystal composition is sandwiched between substrates arranged opposite to each other, and a liquid crystal compound in the liquid crystal composition is turned by applying a voltage to produce a predetermined optical display effect with different gray levels. Therefore, the characteristics of the liquid crystal compound affect the performance of the liquid crystal display device. In order to improve the display effect, it is generally desired that the liquid crystal material has a low rotational viscosity and a high bending elastic constant.

Although the existing liquid crystal materials generally meet the needs, some performances still need to be improved to meet the increasingly stringent requirements of the quality of liquid crystal display devices.

式(1)、

式(2)，     其中，X¹ 與X² 各自獨立地為氟或氫；R¹ 與R² 各自獨立地為C₁ ~C₁₀ 烷基、或C₁ ~C₁₀ 烷氧基，其中該烷基或該烷氧基為未經取代或至少一個-C-C-由-C=C-取代；R³ 為C₁ ~C₃ 烷基，其中該烷基為未經取代或至少一個-C-C-由-C=C-取代；R⁴ 為C₁ ~C₂ 烷基、或C₂ ~C₃ 烯基，其中前述R¹ 、R² 、R³ 及R⁴ 為未經取代或是至少一個碳上的氫被鹵素原子取代。An embodiment of the present invention discloses a liquid crystal composition having a first component including at least one compound represented by formula (1); and a second component including at least one compound represented by formula (2),

Formula 1),

Formula (2), wherein X ¹ and X ² are each independently fluorine or hydrogen; R ¹ and R ² are each independently C ₁ ~C ₁₀ alkyl, or C ₁ ~C ₁₀ alkoxy, wherein the alkyl Group or the alkoxy group is unsubstituted or at least one -CC- is substituted by -C=C-; R ³ is C ₁ ~C ₃ alkyl, wherein the alkyl group is unsubstituted or at least one -CC- -C=C- substituted; R ⁴ is C ₁ ~C ₂ alkyl, or C ₂ ~C ₃ alkenyl, wherein the aforementioned R ¹ , R ² , R ³ and R ⁴ are unsubstituted or on at least one carbon Is replaced by halogen atoms.

Another embodiment of the present invention discloses a liquid crystal display device including: a first substrate; a second substrate, which is opposite to the first substrate; and a liquid crystal layer, located between the first substrate and the second substrate, The liquid crystal layer contains the liquid crystal composition as described above.

The present invention provides a liquid crystal composition including a first component and a second component, wherein the first component includes at least one compound represented by formula (1), and the second component includes at least one compound represented by formula (2). The above liquid crystal composition has excellent display quality, fast response speed, and excellent low-temperature stability. More specifically, the liquid crystal composition of the present invention can maintain good low-temperature stability in a low-temperature storage environment of -20°C.

式(1) 其中X¹ 與X² 各自獨立地為氟或氫； R¹ 與R² 各自獨立地為C₁ ~C₁₀ 烷基、或C₁ ~C₁₀ 烷氧基，其中該烷基或該烷氧基為未經取代或至少一個-C-C-由-C=C-取代； 前述R¹ 及R² 為未經取代或是至少一個碳上的氫被鹵素原子取代。In some embodiments, the first component comprises at least one compound represented by formula (1):

Formula (1) wherein X ¹ and X ² are each independently fluorine or hydrogen; R ¹ and R ² are each independently C ₁ -C ₁₀ alkyl, or C ₁ -C ₁₀ alkoxy, wherein the alkyl or The alkoxy group is unsubstituted or at least one -CC- is substituted by -C=C-; the aforementioned R ¹ and R ² are unsubstituted or hydrogen on at least one carbon is replaced by a halogen atom.

式(2) 其中，R³ 為C₁ ~C₃ 烷基，其中該烷基為未經取代或至少一個-C-C-由-C=C-取代； R⁴ 為C₁ ~C₂ 烷基、或C₂ ~C₃ 烯基，其中 前述R³ 及R⁴ 為未經取代或是至少一個碳上的氫被鹵素原子取代。In some embodiments, the second component comprises at least one compound represented by formula (2):

Formula (2) wherein R ³ is C ₁ ~C ₃ alkyl, wherein the alkyl is unsubstituted or at least one -CC- is substituted by -C=C-; R ⁴ is C ₁ ~C ₂ alkyl, Or C ₂ ~C ₃ alkenyl, wherein the aforementioned R ³ and R ⁴ are unsubstituted or the hydrogen on at least one carbon is replaced by a halogen atom.

Since the following description uses a variety of liquid crystal compounds, in order to express conciseness, the following will use a combination of codes to represent the compound structure, where O represents an oxygen atom; F represents a fluorine atom; and the structural unit corresponding to each code is shown in the following table 1 shown.

Table 1

。It should be noted that in the structural units shown in Table 1, X represents the bonding position of the bonding group at the left end of the structural unit, and Y represents the bonding position of the bonding group at the right end of the structural unit. Furthermore, the numbers displayed on the non-subscript fonts at both ends of the code represent the alkyl group with the carbon number, and the numbers displayed on the non-subscript fonts in the code combination represent the carbon number as the alkyl group of the number. For example, the code 3CP2YO2 represents a compound with the structure:

.

The liquid crystal composition of the present invention includes a first component, wherein the first component includes at least one liquid crystal compound represented by the above formula (1), in other words, the first component may also include two or more of the compounds represented by formula (1) Compounds with different structures. The structure shown in formula (1) is essentially a rod-shaped structure. The rod-shaped structure has a long-axis direction and a short-axis direction. The long-axis direction is the connecting direction of the functional groups R ¹ and R ² , and the short-axis direction is the The long axis direction is perpendicular to the direction.

The structure shown in formula (1) has a cyclic structure of cyclohexane-benzene ring-benzene ring in the long axis direction, and between two adjacent benzene rings, it has an ethyl (-CH ₂ CH ₂ -). The liquid crystal compound having such a structure can maintain good low-temperature stability even when stored in a low-temperature environment of -20°C. Speculation: Compared with the low degree of freedom when the benzene ring-benzene ring is directly bonded, or -O-, -C≡C-bonded, when the benzene ring-benzene ring is connected by an alkyl group, the alkyl group has The single bond can be rotated, so the overall molecular freedom is large, the benzene ring in the molecule can rotate freely, and the molecule is non-linear in the direction of the long axis. In other words, centering on the carbon-carbon single bond in the ethylidene group, the bond between the ethylidene group and the benzene ring on both sides has a spatial asymmetry. Such a structure can destroy the linearity of the rod-shaped structure of the liquid crystal compound in the long axis direction, and thus can increase the stacking stability between the liquid crystal compounds and further improve the low-temperature stability of the liquid crystal compound.

The liquid crystal compound having the structure represented by formula (1) is a cyclohexane-benzene ring-benzene ring in order of ring structure.

In the liquid crystal compound having the structure shown in formula (1), the hydrogen atoms on two adjacent carbon atoms on the terminal benzene ring are replaced by fluorine atoms.

As described above, the liquid crystal compound having the structure represented by formula (1) has a ring structure of cyclohexane-benzene ring-benzene ring, and has an ethyl group between two adjacent benzene rings, and there are The hydrogen atoms on two adjacent carbon atoms are replaced by fluorine atoms, whereby the liquid crystal composition containing the liquid crystal compound of the structure shown in formula (1) can have excellent display quality, fast response speed, and excellent Low temperature stability.

The liquid crystal compound having the structure represented by formula (1) can adjust the characteristics of the liquid crystal compound, such as viscosity, resistance, intermolecular force, etc., by changing the terminal group R ¹ and the terminal group R ² . In some embodiments, in the above formula (1), R ¹ and R ² are each independently C ₁ -C ₁₀ alkyl, or C ₁ -C ₁₀ alkoxy, wherein the alkyl or the alkoxy is Unsubstituted or at least one -CC- is replaced by -C=C-. In other embodiments, in the above formula (1), R ¹ and R ² are each independently C ₁ -C ₅ alkyl, or C ₁ -C ₅ alkoxy, wherein the alkyl or the alkoxy Is unsubstituted or at least one -CC- is replaced by -C=C-.

經取代後成為

；

經取代後成為

或

；或是

經取代後成為

、

、或

。The above "at least one -CC- is replaced by -C=C-" means that at least one CC single bond in the carbon chain is replaced by a double bond. When the carbon chain is a straight chain, the substitution may be in the straight chain, or the straight chain At the end, when the carbon chain has a branch, the substitution may also be in the branch. For example,

Become

;

Become

or

; Or

Become

,

,or

.

According to some embodiments of the present invention, in the above formula (1), X ¹ and X ² are hydrogen atoms, for example: 3CP2YO2, 4CP2YO2, 3CP2YO3.

According to other embodiments of the present invention, in the above formula (1), X ¹ and X ² are fluorine atoms, for example: 3CY2YO2, 4CY2YO2, 3CY2YO3.

Since the first component contains at least one liquid crystal compound represented by the above formula (1), the liquid crystal composition of the present invention has good low-temperature stability. In some embodiments, the liquid crystal compound having the structure of formula (1) is stored in a low-temperature environment at -20°C for no more than 5 days without crystal precipitation.

The liquid crystal composition of the present invention further includes a second component, wherein the second component includes at least one liquid crystal compound represented by the above formula (2). The liquid crystal compound of the structure shown in formula (2) has two cyclohexanes connected, and therefore has better compatibility.

The liquid crystal compound having the structure represented by formula (2) can adjust the characteristics of the liquid crystal compound by changing the functional group R ³ and the functional group R ⁴ . In some embodiments, in the above formula (2), R ³ is C ₁ -C ₃ alkyl.

、

、

、或

，其中R³ 為C₁ ~C₃ 烷基。In some embodiments, the compound represented by formula (2) is,

,

,

,or

, Where R ³ is C ₁ ~C ₃ alkyl.

、

、

、或

。For example, compounds that can be used for the second component include:

,

,

,or

.

式(3) 其中，環A為1,4-伸環己基、1,4-伸苯基，其中，前述環A為未經取代、或環上的氫被氟、或甲基取代； R⁵ 與R⁶ 各自獨立地為C₁ ~C₁₀ 烷基、或C₁ ~C₁₀ 烷氧基，其中該烷基或該烷氧基為未經取代或至少一個-C-C-由-C=C-取代； Z¹ 為單鍵、-CH₂ CH₂ -、-CH₂ O-、-OCH₂ -、-COO-或-OCO-； l=1、2、或3，其中，當l＞1時，環A為彼此相同或彼此不同，Z¹ 為彼此相同或彼此不同；且排除式(1)所示化合物。The liquid crystal composition of the present invention may further include a third component, wherein the third component includes at least one liquid crystal compound represented by formula (3):

Formula (3) wherein ring A is 1,4-cyclohexyl or 1,4-phenylene, wherein ring A is unsubstituted, or hydrogen on the ring is substituted by fluorine or methyl; R ⁵ And R ⁶ are each independently C ₁ -C ₁₀ alkyl, or C ₁ -C ₁₀ alkoxy, wherein the alkyl or alkoxy is unsubstituted or at least one -CC-by-C=C- Substitution; Z ¹ is a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -COO-, or -OCO-; l=1, 2, or 3, where when l>1 , Ring A is the same as or different from each other, Z ¹ is the same as or different from each other; and the compound represented by formula (1) is excluded.

、

、

、

、

、

、

、或

，其中R⁵ 與R⁶ 各自獨立地為C₁ ~C₁₀ 烷基、或C₁ ~C₁₀ 烷氧基，其中該烷基或該烷氧基為未經取代或至少一個-C-C-由-C=C-取代。In some embodiments, the third component is

,

,

,

,

,

,

,or

, Wherein R ⁵ and R ⁶ are each independently C ₁ -C ₁₀ alkyl, or C ₁ -C ₁₀ alkoxy, wherein the alkyl or alkoxy is unsubstituted or at least one -CC-from- C=C- replaced.

The liquid crystal compound having the structure represented by formula (3) can adjust the characteristics of the liquid crystal compound by changing the functional group R ⁵ and the functional group R ⁶ . For example, compounds that can be used for the third component include, but are not limited to: 2CPYO2, 3CPYO2, 3CPYO4, 3C1OYO1, 3C1OYO2, 3CYO2, 5CYO2, or 3CCYO2.

In some embodiments, the liquid crystal composition may further include a third component in addition to the first component and the second component. In some embodiments, based on the total weight of the liquid crystal composition being 100 parts by weight, the content range of the first component may be about 0.1-30 parts by weight, for example, 0.1-20 parts by weight, 0.1-15 parts by weight; The content range of the second component may be about 5-50 parts by weight, for example, 10-40 parts by weight, 10-30 parts by weight; the third component, for example, may be about 10-95 parts by weight, 20-90 parts by weight, 30 -70 parts by weight.

式(4) 其中，環B及環C各自獨立地為1,4-伸環己基、1,4-伸苯基、2-氟-1,4-伸苯基、3-氟-1,4-伸苯基或、茚滿-2,5-二基； R⁷ 與R⁸ 各自獨立地為C₁ ~C₁₀ 烷基、或C₁ ~C₁₀ 烷氧基，其中該烷基或該烷氧基為未經取代或至少一個-C-C-由-C=C-取代； Z² 為單鍵、-CH₂ CH₂ -、-CH₂ O-、-OCH₂ -、-COO-或-OCO-； m=1、2、或3，其中，當m＞1時，環B為彼此相同或彼此不同，Z² 為彼此相同或彼此不同；且排除式(2)所示化合物。The liquid crystal composition of the present invention may further include a fourth component, wherein the fourth component includes at least one liquid crystal compound represented by formula (4):

Formula (4) wherein ring B and ring C are each independently 1,4-cyclohexyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4 -Phenylene or indan-2,5-diyl; R ⁷ and R ⁸ are each independently C ₁ -C ₁₀ alkyl, or C ₁ -C ₁₀ alkoxy, wherein the alkyl or the alkyl Oxygen is unsubstituted or at least one -CC- is substituted by -C=C-; Z ² is a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -COO- or -OCO -; m=1, 2, or 3, wherein when m>1, rings B are the same as or different from each other, and Z ² is the same or different from each other; and the compound represented by formula (2) is excluded.

The liquid crystal compound having the structure represented by formula (4) can adjust the characteristics of the liquid crystal compound by changing the functional group R ⁷ and the functional group R ⁸ . For example, compounds that can be used for the fourth component include, but are not limited to: 3CC5, 3CPO2, 3CCP1, or 3CPP2.

In some embodiments, the liquid crystal composition may further include a fourth component in addition to the first component and the second component. In some embodiments, based on the total weight of the liquid crystal composition being 100 parts by weight, the content of the fourth component may be about 1-70 parts by weight, for example, 5-50 parts by weight and 5-40 parts by weight.

The first component includes at least one structure represented by formula (1). Since the structure represented by formula (1) has an asymmetry in a three-dimensional structure, low-temperature stability can be increased. When the content of the first component is less than 0.1 parts by weight, the function of increasing the low-temperature stability with an asymmetric three-dimensional structure cannot be exerted; when the content of the first component is greater than 30 parts by weight, the proportion of the asymmetric structure is too large, increasing the stacking Difficulty, reduce low temperature stability.

式(5) 其中，環D與環E各自獨立地為1,4-伸環己基、1,4-伸苯基、萘-2,6-二基、茚滿-1,5-二基、或茚滿-2,5-二基，其中，前述環D與環E為未經取代、或環上的氫被氟、或甲基取代；     P為

、

、

、

、

、

、或

；     Sp為單鍵、或C₁ ~C₁₂ 伸烷基，其中該伸烷基為未經取代或至少一個-CH₂ -被-O-取代；     R⁹ 為C₁ ~C₁₂ 烷基、C₁ ~C₁₂ 烷氧基、C₂ ~C₁₂ 烯基或-Sp-P，其中，烯基為未取代或是碳上的氫被氟取代；     Z³ 為單鍵、-CH₂ CH₂ -、-CH₂ O-、-OCH₂ -、-COO-、-OCO-、或M-X₂ ，         其中M為C、或Si；X為H、CH₃ 、或CF₃ ；且     n為0、1、2、3、或4，當n＞1時，環D為彼此相同或彼此不同，Z³ 為彼此相同或彼此不同。The liquid crystal composition of the present invention may further include a polymerizable compound for polymerizing the liquid crystal compound. The polymerizable compound has the structure shown in formula (5):

Formula (5) wherein ring D and ring E are each independently 1,4-cyclohexyl, 1,4-phenylene, naphthalene-2,6-diyl, indan-1,5-diyl, Or indan-2,5-diyl, wherein the aforementioned ring D and ring E are unsubstituted, or the hydrogen on the ring is substituted by fluorine or methyl; P is

,

,

,

,

,

,or

; Sp is a single bond, or C ₁ ~C ₁₂ alkylene, wherein the alkylene is unsubstituted or at least one -CH ₂ -is substituted by -O-; R ⁹ is C ₁ ~C ₁₂ alkyl, C ₁ ~C ₁₂ alkoxy, C ₂ ~C ₁₂ alkenyl or -Sp-P, wherein the alkenyl is unsubstituted or the hydrogen on the carbon is replaced by fluorine; Z ³ is a single bond, -CH ₂ CH _2- , -CH ₂ O-, -OCH ₂ -, -COO-, -OCO-, or MX ₂ , where M is C, or Si; X is H, CH ₃ , or CF ₃ ; and n is 0, 1, 2, 3, or 4, when n>1, rings D are the same as or different from each other, and Z ³ is the same or different from each other.

In some embodiments, the liquid crystal composition may further include a polymerizable compound in addition to the first component and the second component. In such an embodiment, based on the total weight of the liquid crystal composition being 100 parts by weight, the content of the polymerizable compound may range from about 0.01 to 5 parts by weight, for example, from 0.05 to 1 part by weight.

Those of ordinary skill in the art should understand that the aforementioned liquid crystal composition may further include other than the above formula (1), formula (2), formula (3), formula (4) or formula (5) Liquid crystal compounds, or other additives in appropriate amounts. In some embodiments, other additives may include, for example, chiral dopants, UV stabilizers, antioxidants, free radical scavengers, nanoparticles, and the like.

The present invention also provides a liquid crystal display device using the above liquid crystal composition. FIG. 1 is a schematic cross-sectional view illustrating a liquid crystal display device 100 according to some embodiments of the present invention.

Referring to FIG. 1, the liquid crystal display device 100 may include a first substrate 110, a second substrate 120 opposite to the first substrate 110, and a liquid crystal layer 130 between the first substrate 110 and the second substrate 120. Each of the first substrate and the second substrate may be a thin film transistor substrate and a color filter substrate currently known or developed in the future. In order to simplify the description, the materials, structures and forming methods of the first substrate 110 and the second substrate 120 will not be described in detail here.

The liquid crystal layer 130 of the liquid crystal display device 100 of the present invention uses the above liquid crystal composition, wherein the liquid crystal composition includes at least one liquid crystal compound represented by formula (1) and at least one liquid crystal compound represented by formula (2). As described above, since the liquid crystal compound represented by the formula (1) has good low-temperature stability, by including the liquid crystal compound represented by the formula (1) in the liquid crystal composition, the liquid crystal display device can have excellent low-temperature stability. In addition, by selecting the first component, the second component, and/or the third component used in the liquid crystal composition and adjusting the weight ratio, the rotational viscosity of the liquid crystal composition can be adjusted to a desired range. In this way, the liquid crystal display device using the above liquid crystal composition has better display quality and fast response speed.

The liquid crystal composition of the present invention can be applied to all liquid crystal display devices. In some embodiments, the liquid crystal composition of the present invention has excellent low-temperature stability, and the liquid crystal does not precipitate at low temperatures, so it can be applied to liquid crystal display devices exposed to low-temperature environments, such as car navigation systems, smart Watches, etc. In other embodiments, the liquid crystal composition of the present invention can also be applied to other types of liquid crystal display devices.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, several examples are given below to illustrate the liquid crystal composition of the present invention. Since various liquid crystal compounds are used in the examples and comparative examples of the present invention, for simplicity of expression, the following will be represented by a combination of codes, and the structural units corresponding to each code are shown in Table 1 above.

In this specification, taking 3CP2YO2 as an example, a method of synthesizing a liquid crystal compound represented by formula (1) will be described.

化合物1                                                                3CP2YO2[Preparation Example 1] Preparation of liquid crystal compound 3CP2YO2

Compound 1 3CP2YO2

Place compound 1 (10 mmol, Hebei North Star Chemical Co., Ltd., trade name: 3CPTYO2) in a 500 mL reaction flask, add 120 mL of a 1:5 mixed solution of toluene and ethanol, and stir to dissolve. At room temperature, slowly add Pd/C as a palladium catalyst (0.2 g, Youhe Trading Co., Ltd., trade name: palladium metal 10%/activated carbon 90%) into the reaction bottle, and hydrogen gas is introduced at room temperature. Let it react for 24 hours. After the reaction was completed, the catalyst was filtered off, and the collected organic solvent was removed using a rotary concentrator to obtain 3CP2YO2 (white solid).

The liquid crystal compound 3CP2YO2 was analyzed with a gas chromatography mass spectrometer. The obtained spectrum is shown in FIG. 2, where the mass-to-charge ratio (m/z) is 386, which is consistent with the molecular weight of the compound 3CP2YO2.

According to the above preparation process, in the initial preparation step, using different compounds having an alkyne bonding structure as the starting reactant, the final product having an alkane bonding structure can be obtained. Through the above-mentioned preparation reaction, the linear symmetric alkyne bonding structure in the compound is transformed into an alkane bonding structure without linear symmetry, thus destroying the linear symmetry of the compound.

[Example] Preparation of liquid crystal composition

The liquid crystal composition of the present invention is prepared by directly mixing all the liquid crystal compounds of the first, second, third, and fourth components according to the contents shown in Tables 2 and 4 below. The methods for measuring the properties of the liquid crystal composition examples and comparative examples of the present invention are as follows. The measurement results of various properties are also shown in Table 2 and Table 4. It should be noted that in Tables 2 and 4, the content unit of the liquid crystal compound is parts by weight (calculated based on the total weight of the liquid crystal composition being 100 parts by weight).

[Example 1] The first component uses 7 parts by weight of 3CP2YO2, and the second component uses 24.5 parts by weight of 3CC2 (Jiangsu Hecheng New Materials Co., Ltd., trade name: 3CC2). The first component and the second component were adjusted to the above ratios, and the types and ratios of the liquid crystal compounds of the third and fourth components shown in Table 2 were referred to so that the total weight of the liquid crystal composition was 100 parts by weight. In addition, commercially available products can be used for the third component and the fourth component.

[Comparative Example 1-5] According to the types and ratios of the liquid crystal compounds of the first component, the second component, the third component and the fourth component shown in Table 2, the liquid crystal composition is formulated.

[Example 2-11] According to the types and ratios of the liquid crystal compounds of the first component, the second component, the third component, and the fourth component shown in Table 2, the liquid crystal composition is formulated.

[Measurement of properties of liquid crystal composition]

Dielectric anisotropy (Δε)

The liquid crystal compound was packed into a liquid crystal cell with an average interval of 6 μm, and a voltage of 0V to 30V was applied to the liquid crystal cell at a temperature of 25°C. The average dielectric constant measured in the direction parallel to the long axis of the liquid crystal molecule is ε∥; the average dielectric constant measured in the direction perpendicular to the long axis of the liquid crystal molecule is ε⊥. Dielectric anisotropy (Δε) is the difference between ε∥ and ε⊥ (that is, Δε = ε∥-ε⊥).

Rotating viscosity (γ1)

The liquid crystal composition is put into a liquid crystal cell with an average interval of 6 μm, and a voltage of 30 V is applied to the liquid crystal cell at a temperature of 25° C. The dielectric anisotropy (Δε) factor conversion is added by the instrument to obtain the rotational viscosity ( γ1), the unit is mPa•S.

Bending elastic constant K33

The liquid crystal composition is filled into a liquid crystal cell with an average interval of 6 μm, and a voltage of 20 V is applied to the liquid crystal cell at a temperature of 25° C. The dielectric anisotropy (Δε) factor conversion is added by the instrument to obtain K33 (in PN at 25°C).

LTS (low temperature storage) days of low temperature storage

Put 0.3g of liquid crystal composition into a 7mL glass bottle, and then put the glass bottle into a constant temperature low temperature freezer at -20°C, and observe whether there is crystal precipitation of liquid crystal every day. The number of days without crystal precipitation is taken as the number of days of low-temperature storage (D). The longer the number of days, the higher the low-temperature stability.

Table 2

Referring to Table 2, the liquid crystal compositions of Examples 1 to 12 contain at least one first component having the structure represented by formula (1) and at least one second component having the structure represented by formula (2), In contrast, Comparative Examples 1 to 5 did not contain the above ingredients at the same time. The results show that the viscosity-elastic constant (γ1/K33) of the liquid crystal composition containing the first component of the structure represented by formula (1) and the second component of the structure represented by formula (2) is relatively Low, with excellent response speed, and relatively low temperature storage days, with excellent low temperature stability.

[Example 13] According to the components and ratios of the liquid crystal composition of Example 1 shown in Table 2, a liquid crystal composition was prepared as a mother liquor. With the total weight of the liquid crystal composition being 100 parts by weight, 0.39 parts by weight of BMA as a polymerizable compound was added to 99.7 parts by weight of the mother liquor, and the polymer stabilized alignment (PSA) process step was performed to make the liquid crystal composition物聚。 Material polymerization. The PSA process condition is that the test piece is applied with a voltage of 12V, irradiated under a UV lamp, and after confirming the process that Ton falls below 10ms, the UV process is ended.

[Examples 14-16] A liquid crystal composition was prepared according to the same procedure as in Example 13 except that the type of polymerizable compound was changed as shown in Table 4. According to the same process, the liquid crystal composition is polymerized.

Measurement of Toff and Ton before and after the process

The response speed is measured by using a halogen lamp as the incident light source, adjusting the polarizer and the light detection plate to be in an orthogonal state, and measuring the amount of change in penetration of a rectangular wave (at 60 Hz and 5.5 V) applied to the liquid crystal composition. The response speed is the time (ms) required to measure the penetration rate T from T10 to T90 at this voltage. The shorter the time, the faster the response speed. In the polymer stable alignment liquid crystal, Ton is defined as the time required from T10 to T90; Toff is the time required from T90 to T10. Toff and Ton were measured before and after the PSA process.

The codes of the polymerizable compounds shown in Table 4 are explained as follows: Table 3 Polymerizable compounds

Table 4

Please refer to Table 4. The liquid crystal compositions of Examples 13 to 16 all contain a first component having at least one structure represented by formula (1) and at least one second component having a structure represented by formula (2). After the PSA process, the polymerizable compounds can all achieve the effect of reducing Ton.

It can be seen from the above examples that the liquid crystal composition has excellent display by containing the first component having at least one structure represented by formula (1) and at least one second component having the structure represented by formula (2) The quality and response speed are fast, and it has excellent low temperature stability. It is particularly suitable as a liquid crystal display device that needs to be used in a low-temperature environment.

Although the present invention has been disclosed in several preferred embodiments as above, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make any changes without departing from the spirit and scope of the present invention. And retouching, therefore, the scope of protection of the present invention shall be subject to the scope defined in the appended patent application.

100: liquid crystal display device 110: first substrate 120: second substrate 130: liquid crystal layer

FIG. 1 is a schematic cross-sectional view illustrating a liquid crystal display device according to some embodiments of the present invention. Figure 2 is a gas chromatography mass spectrometry analysis pattern of the product according to one of the preparation examples of the present invention.

100: liquid crystal display device

110: the first substrate

120: second substrate

130: liquid crystal layer

Claims (13)

A liquid crystal composition comprising, a first component comprising at least one compound represented by formula (1); and a second component comprising at least one compound represented by formula (2),

Formula 1),

Formula (2), wherein X ¹ and X ² are each independently fluorine or hydrogen; R ¹ and R ² are each independently C ₁ ~C ₁₀ alkyl, or C ₁ ~C ₁₀ alkoxy, wherein the alkyl Group or the alkoxy group is unsubstituted or at least one -CC- is substituted by -C=C-; R ³ is C ₁ ~C ₃ alkyl, wherein the alkyl group is unsubstituted or at least one -CC- -C=C- substituted; R ⁴ is C ₁ ~C ₂ alkyl, or C ₂ ~C ₃ alkenyl, wherein the aforementioned R ¹ , R ² , R ³ and R ⁴ are unsubstituted or on at least one carbon Is replaced by halogen atoms. The liquid crystal composition as described in item 1 of the patent application range, wherein X ¹ and X ^{2 of the} compound represented by formula (1) are each independently fluorine or hydrogen; R ¹ and R ² are independently C ₁ ~C ₅ alkyl groups, or C ₁ -C ₅ alkoxy groups, the aforementioned alkyl groups and alkoxy groups are unsubstituted or hydrogen on at least one carbon is replaced by fluorine. The liquid crystal composition as described in item 1 of the patent application, wherein the compound represented by formula (2) is,

,

,

,or

, Where R ³ is C ₁ ~C ₃ alkyl. The liquid crystal composition as described in item 1 of the patent application, wherein the compound represented by formula (2) is

,

,

,or

. The liquid crystal composition according to item 1 of the patent application scope, which further includes a third component, including at least one compound represented by formula (3),

Formula (3) wherein ring A is 1,4-cyclohexyl or 1,4-phenylene, wherein ring A is unsubstituted, or hydrogen on the ring is substituted by fluorine or methyl; R ⁵ And R ⁶ are each independently C ₁ -C ₁₀ alkyl, or C ₁ -C ₁₀ alkoxy, wherein the alkyl or alkoxy is unsubstituted or at least one -CC-by-C=C- Substitution; Z ¹ is a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -COO-, or -OCO-; l=1, 2, or 3, where when l>1 , Ring A is the same as or different from each other, Z ¹ is the same as or different from each other; and the compound represented by formula (1) is excluded. The liquid crystal composition as described in item 5 of the patent application scope, wherein the third component is

,

,

,

,

,

,

,or

, Wherein R ⁵ and R ⁶ are each independently C ₁ -C ₁₀ alkyl, or C ₁ -C ₁₀ alkoxy, wherein the alkyl or alkoxy is unsubstituted or at least one -CC-from- C=C- replaced. The liquid crystal composition as described in item 1 of the patent application scope, which further includes a fourth component, including at least one compound represented by formula (4),

Formula (4) wherein ring B and ring C are each independently 1,4-cyclohexyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4 -Phenylene or indan-2,5-diyl; R ⁷ and R ⁸ are each independently C ₁ -C ₁₀ alkyl, or C ₁ -C ₁₀ alkoxy, wherein the alkyl or the alkyl Oxygen is unsubstituted or at least one -CC- is substituted by -C=C-; Z ² is a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -COO- or -OCO -; m=1, 2, or 3, wherein when m>1, rings B are the same as or different from each other, and Z ² is the same or different from each other; and the compound represented by formula (2) is excluded. The liquid crystal composition as described in item 5 of the patent application scope, which further includes a fourth component, including at least one compound represented by formula (4),

Formula (4) wherein ring B and ring C are each independently 1,4-cyclohexyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4 -Phenylene or indan-2,5-diyl; R ⁷ and R ⁸ are each independently C ₁ -C ₁₀ alkyl, or C ₁ -C ₁₀ alkoxy, wherein the alkyl or the alkyl Oxygen is unsubstituted or at least one -CC- is substituted by -C=C-; Z ² is a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -COO- or -OCO -; m=1, 2, or 3, wherein when m>1, rings B are the same as or different from each other, and Z ² is the same or different from each other; and the compound represented by formula (2) is excluded. The liquid crystal composition as described in item 7 or 8 of the patent application scope further includes a polymerizable compound. The liquid crystal composition as described in item 9 of the patent application scope, wherein the polymerizable compound has a structure represented by formula (5),

Formula (5) wherein ring D and ring E are each independently 1,4-cyclohexyl, 1,4-phenylene, naphthalene-2,6-diyl, indan-1,5-diyl, Or indan-2,5-diyl, wherein the aforementioned ring D and ring E are unsubstituted, or the hydrogen on the ring is substituted by fluorine or methyl; P is

,

,

,

,

,

,or

; Sp is a single bond, or C ₁ ~C ₁₂ alkylene, wherein the alkylene is unsubstituted or at least one -CH ₂ -is substituted by -O-; R ⁹ is C ₁ ~C ₁₂ alkyl, C ₁ ~C ₁₂ alkoxy, C ₂ ~C ₁₂ alkenyl or -Sp-P, wherein the alkenyl is unsubstituted or the hydrogen on the carbon is replaced by fluorine; Z ³ is a single bond, -CH ₂ CH _2- , -CH ₂ O-, -OCH ₂ -, -COO-, -OCO-, or MX ₂ , where M is C, or Si; X is H, CH ₃ , or CF ₃ ; and n is 0, 1, 2, 3, or 4, when n>1, the rings D are the same as or different from each other, and Z ³ is the same as or different from each other. The liquid crystal composition according to any one of items 1 to 8 of the patent application range, wherein the first component accounts for 0.1 to 30 parts by weight based on the total weight of the liquid crystal composition as 100 parts by weight, and the second Ingredients account for 5~50 parts by weight. The liquid crystal composition as described in item 9 of the patent application scope, wherein the first component accounts for 0.1 to 30 parts by weight and the second component accounts for 5 to 50 parts by weight based on the total weight of the liquid crystal composition as 100 parts by weight Copies. A liquid crystal display device includes: a first substrate; a second substrate opposite to the first substrate; and a liquid crystal layer between the first substrate and the second substrate, wherein the liquid crystal layer includes The liquid crystal composition described in any one of items 1 to 12 in the patent application range.

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